Andy,On most toilets, the water from the fill valve will keep filling through the overflow, past the time when the bowl has filled. Most toilets however have molded in traps that are quiet. Unifit adapters on the skirted toilets are made of plastic and transmit the dripping sound well. The idea behind the "reducer" on the end of the fill valve tubing is to put in just the right amount of water. ( More of Less )There will still be some dripping though.

You can notice dripping sounds in other areas of the house too. When most tub/shower units are used, it can take up to 30 minutes for the water to "drip" out of the shower head standpipe. Just thought I would throw that one in, I hope you won't be listening more intently to that drip now. Terry Love